We have proposed a CT system design to rapidly produce volumetric images with negligible cone beam artifacts. The investigated system uses a large array scanned source with a smaller array of fast detectors. The x-ray source is electronically steered across a 2D target every few milliseconds as the system rotates. The proposed reconstruction algorithm for this system is a modified 3D filtered backprojection method. The data are rebinned into 2D parallel ray projections, most of which are tilted with respect to the axis of rotation. Each projection is filtered with a 2D kernel and backprojected onto the desired image matrix. To ensure adequate spatial resolution and low artifact level, we rebin the data onto an array that has sufficiently fine spatial and angular sampling. Due to finite sampling in the real system, some of the rebinned projections will be sparse, but we hypothesize that the large number of views will compensate for the data missing in a particular view. Preliminary results using simulated data with the expected discrete sampling of the source and detector arrays suggest that high resolution (<0.5 mm in all directions) images can be obtained in a single rotation with the proposed system and reconstruction algorithm.
[1]
Edward G. Solomon,et al.
Scanning-beam digital x-ray (SBDX) system for cardiac angiography
,
1999,
Medical Imaging.
[2]
A. Macovski,et al.
Selection of a convolution function for Fourier inversion using gridding [computerised tomography application].
,
1991,
IEEE transactions on medical imaging.
[3]
Bruce D. Smith.
Cone-beam tomography: recent advances and a tutorial review
,
1990
.
[4]
N J Pelc,et al.
Utilization of Cross‐Plane Rays for Three‐Dimensional Reconstruction by Filtered Back‐Projection
,
1979,
Journal of computer assisted tomography.
[5]
J. D. O'Sullivan,et al.
A Fast Sinc Function Gridding Algorithm for Fourier Inversion in Computer Tomography
,
1985,
IEEE Transactions on Medical Imaging.